If you weren’t done watching tech giants get grilled by lawmakers, mark your calendar for September 26 in what’s expected to be another riveting round of questioning.

Policy chiefs from AT&T and Charter, along with senior executives at Apple, Amazon, Google and Twitter will face questions from the Senate Commerce Committee later this month about how each company approaches safeguards to consumer privacy. The tech and telco companies will be asked to “discuss possible approaches to safeguarding privacy more effectively,” among other things.

Noticeably absent is Facebook; though the committee says the witness list is subject to change.

Committee chairman Sen. John Thune said the hearing will allow the companies to “explain their approaches to privacy, how they plan to address new requirements from the European Union and California, and what Congress can do to promote clear privacy expectations without hurting innovation.”

Beyond that, it’s not clear exactly what the point of the hearing is.

A congressional source told TechCrunch to expect each company to explain for one what they could do to protect privacy outside of the law, and what role Congress can play in creating a single set of privacy requirements.

This will be the second Senate Commerce Committee hearing this year focused on the issue. Facebook chief executive Mark Zuckerberg was called to testify in April and later the Senate Intelligence Committee has held several hearings to discuss election security and disinformation campaigns around the 2018 midterm elections.